This application is for the establishment of the Digestive Diseases Research Core Center (DDRCC) at Washington University Medical School (WUMS), St. Louis, focusing on regulatory factors in the GI tract. The concept of a DDRCC has emerged from the collaborative and synergistic interactions of a large number of investigators engaged in digestive-diseases related research, and will include thirty-six principal investigators in the clinical and basic science departments of the Washington University School of Medicine as full members. The goals for the DDRCC at Washington University are to 1) formalize and provide mechanisms for expanding the extensive collaborative and synergistic interactions already in place between a large number of independently funded investigators engaged in digestive-diseases related research; 2) pool departmental and divisional resources to provide services and expertise that may otherwise not be available to individual investigators, in a cost-effective manner; and 3) provide funding support for investigators to develop new digestive-diseases related research initiatives that will subsequently be competitive for more conventional mechanisms of funding. The components of the DESCRIPTION (Taken directly from the application) DDRCC include a Transgenic Mouse/Stem Cell Core Facility, a Morphology Core Facility, Cell Biology Core facility and a Protein Structure and Macromolecular Graphics Core Facility. These four cores are designed to facilitate analysis of the regulatory factors in the GI tract both in vivo and in vitro, and to correlate structure with function. These cores in many cases will be expanded from existing mini-facilities. The Administrative Core will oversee the operation of the DDRCC as a whole. It will also administer the P/F program to foster participation by younger and established investigators in digestive-diseases related research. In addition, the NIH-sponsored General Clinical Research Center at Washington University will provide DDRCC participants with resources for conducting clinical research, and is currently being utilized by several key members of the DDRCC who are experts in translational GI research. Taken together, these components and objectives define the DDRCC at the Washington University School of Medicine.